Polyamides are compounds that have a wide variety of commercially significant end uses. As an example, the polymers are typically formed into fibers which may be used in materials exhibiting high tensile strength and modulus. Common polyamides include, for example, nylon 6 and nylon 6,6. These specific polyamides are especially advantageous when used in fibers employed in apparel, tire cords, and engineering resins.
Polyamides are commonly formed by various types of reaction schemes. A commercially popular reaction scheme is one involving melt polycondensation. In a melt polycondensation reaction, a diamine and a diacid are typically combined to form a salt, often referred to as a nylon salt. The nylon salt is then heated and the water is driven off. By controlling the efficiency of water removal, the molecular weight of the resulting polyamide can be managed.
In spite of the widespread commercial acceptance of the melt polycondensation reaction, a need in the art remains for a process which is more efficient. In particular, it would be advantageous to have a polyamide synthesis reaction which utilizes lower temperatures and shorter reaction times. Moreover, it would be desirable to conduct the reaction in a medium which is potentially more environmentally acceptable than a medium comprising an aqueous solution and organic solvents.
It is therefore an object of the present invention to provide a method of forming polyamides which uses a more potentially acceptable environmental reaction medium, along with lower temperatures and shorter reaction times.